1. Field of the Invention
The present invention relates to the deployment of sonobuoys, more particularly to a device that enables the deployment of sonobuoys by air from a ship without the need of a manned or recoverable unmanned aircraft.
2. Description of the Prior Art
Sonobuoys have been used for decades as a method of tracking and detecting submarines, relying on acoustic sensors to detect submarine noises. Currently, these expendable devices are deployed from helicopters or fixed wing aircraft. Although the performance of these manned aircraft is effective, there still remains a risk to the flight crew when deploying sonobuoys in areas where an enemy threat exists at the desired sonobuoy drop location, such as over water near a hostile coastline. To address this problem, there have been experimental uses of a small number of unmanned air vehicles over the last few decades for the delivery of sonobuoys from a ship to a remote location, but these vehicles are large and expensive, and as such they must retain sufficient energy on-board after deploying the sonobuoys to return to the ship to be recovered.
There exist a number of patents describing alternatives to manned aircraft methods of sonobuoy deployment. In U.S. Pat. No. 6,082,675, Woodall describes both an air-launched, glider configuration, and a surface-launched drone configuration. The glider configuration in this patent requires a separate aircraft to transport and release the glider. The drone configuration described in this example is imagined to a be a complete aircraft independent of the sonobuoy, to which the sonobuoy is temporarily connected and, once the sonobuoy has been dropped at a designated site, the drone flies back to be recovered at its launch point.
U.S. Pat. No. 5,973,994 to Woodall describes a method of delivering a sonobuoy by making use of mortar or rocket launchers, which describes the adaptation of sonobuoys for use in ship based mortar or rocket launchers, as well as stabilizing fins for use during its arced trajectory.
U.S. Pat. No. 6,498,767 to Carreiro describes a method of delivering sonobuoys by adapting them to be deployed by a cruise missile, in turn requiring a large complex and expensive vehicle (the cruise missile) to deliver multiple sonobuoys. The cruise missile described in this example is considered to have turbine propulsion, as is typical of high-speed cruise missile weapons.
Although not directly related to sonobuoys, the prior art in guided munitions is in a similar field of invention. In U.S. Pat. No. 6,237,496, Abbot describes a GPS guided munition, wherein a tailfin assembly is retrofitted to a munition so as to facilitate guidance of the munition. In U.S. Pat. No. 5,615,846, Shmoldas describes an extendable wing for guided missiles and munitions, where a wing kit is attached to a munition to act as a range extender. In U.S. Pat. No. 6,293,202, Woodall describes an airborne deployed GPS guided torpedo.
From these, it can be observed that there exist patents for various means of air delivery of standard naval sonobuoys without the use of manned aircraft, but their still remains a need for a small (portable), cost effective device to remotely deploy sonobuoys. It is the object of this invention to provide a flight kit that can be retrofitted onto existing navy sonobuoys to enable them to become self-deployable, wherein the sonobuoy itself is the central structural load-bearing component of the delivery assembly.